水蜡树果实总黄酮抗脂质过氧化作用

Anti-peroxidation of Total Flavonoids from Fruits of Ligustrum obtusifolium on Lipids

【目的】初步探究水蜡树果实总黄酮的抗脂质过氧化作用。【方法】用分光光度法测定水蜡树果实总黄酮对DPPH·自由基和羟自由基(·OH)的清除率,分析其对小鼠肝匀浆中自氧化和诱导(FeSO4和H2O2)生成的丙二醛(MDA)含量、Fe^2+与抗坏血酸(Vc)诱导的小鼠肝线粒体肿胀度、H2O2诱导的小鼠红细胞氧化溶血、氧化氢酶(CAT)和谷胱甘肽过氧化氢酶(GSH-Px)活性及谷胱甘肽(GSH)含量的影响。【结果】水蜡树果实总黄酮对DPPH·自由基和·OH自由基具有一定的清除能力,IC50分别为(0.45±0.01) g·L^-1和(1.57±0.12)g·L^-1;1.0~6.0 g·L^-1水蜡树果实总黄酮能抑制自氧化体系中MDA的生成;0.5~6.0 g·L^-1总黄酮可降低FeSO4诱导条件下MDA的生成;2.0~6.0 g·L^-1总黄酮可抑制H_2O_2诱导条件下MDA的生成;0.5~10.0 g·L^-1总黄酮能明显减缓Fe^2+与Vc诱导的肝线粒体悬液OD520值的下降,2.0~10.0 g·L^-1总黄酮可明显减弱H2O2诱导红细胞的溶血度;0.6~4.0g·L^-1总黄酮可显著提高CAT和GSH-Px的活性及GSH的含量。【结论】水蜡树果实总黄酮可减弱小鼠肝组织自发性过氧化和诱导脂质过氧化,抑制小鼠肝线粒体和红细胞的氧化损伤,提高抗氧化酶的活性及非酶抗氧化物的含量。本研究对水蜡树果实天然抗氧化剂的开发有一定的借鉴意义。

【Objective】Anti-peroxidation effec to fthe flavonoids extracted from fruits ofL igustrum obtusifoliumo n lipids was investigated.【Method】Scavenging capacities of the crude extract on DPPH·and hydroxyl(·OH)free radicals were tested using spectrophotometry.Effects of the flavonoids on the malondialdehyde(MDA)content in rat liver homogenate upon spontaneous oxidation or peroxidation by either FeSO4 or H2O2 induction and the mitochondrial swelling on rat liver induced by Fe2+and ascorbic acid(Vc)as well as the hemolysis of red blood cells(RBCs)induced by H2O2 were assessed in vitro.And the activity of the catalase(CAT)and glutathione peroxidase(GSH-Px)and the level of the glutathione(GSH)were tested in vivo.【Result】The flavonoid extract exhibited abilities in scavenging DPPH·and·OH free radicals with IC50 of(0.45±0.01)g·L−1 and(1.57±0.12)g·L−1,respectively.From the concentration of 1.0 g·L−1 to 6.0 g·L−1,the extract significantly reduced the in vitro MDA in rat liver homogenate under spontaneous oxidation;from 0.5 g·L−1 to 6.0 g·L−1,under FeSO4 induction;and,from 2.0 g·L−1 to 6.0 g·L−1 under H2O2 induction.From 0.5 g·L−1 to 10.0 g·L−1,the flavonoids also suppressed the liver mitochondrial swelling induced by Fe2+and Vc;while,from 2.0 g·L−1 to 10.0 g·L−1,the RBC hemolysis induced by H2O2,and those from 0.6 g·L−1 to 4.0 g·L−1 could enhance the level of CAT,GSH,and GSH-Px.【Conclusion】The crude flavonoid extract from the fruits of L.obtusifolium significantly inhibited in vitro on both spontaneous and induced lipid peroxidation reducing the oxidative damage on the mitochondria and RBCs of rat liver,and enhance the acitivity of antioxidant enzymes and the content of non-enzyme antioxidants.The results suggested a promising potential in developing a natural antioxidant from the fruits.